The Yukos headquarters in Moscow (CTK)
May 11, 2007 -- A little-known Russian company has bought the last remaining assets of the bankrupt Yukos oil company, including its multi-story headquarters in Moscow.

The firm Prana bought the assets for $3.9 billion at an auction today.

On May 10, Russian state-run oil company Rosneft bought the Samaraneftegaz facility, Yukos's last production and refining assets, for $6.4 billion.

The purchase adds to a recent series of acquisitions that have transformed Rosneft from a loose bundle of assets into a dominant player in Russia's oil market.

Yukos was driven into bankruptcy after it was hit with billions of dollars in back taxes and its chief executive, Mikhail Khodorkovsky, was jailed on fraud and tax evasion charges in 2003.